The way to tell, is look at floor, if hatches are present, lift a few and look for water (clean and waste) tanks. There will also be lockers in the floor about 6 or 9" deep.
My B544 is on Fiat Maxi chassis and has double floor, I don't know where this idea that only Allko chassis have double floor.
My B544 is on Fiat Maxi chassis and has double floor, I don't know where this idea that only Allko chassis have double floor.